Where does SPA get the means from when displaying NAPLAN data inside SPAstandard?

All our means come directly from ACARA. ACARA produces two sets of means: firstly, those published via their summary national report. These are the means we use when we first release NAPLAN data to SPA around September each year.  In around February the following year, ACARA publish the final national and state means, which will differ because of some further adjustments they make. SPA re-adjusts the means inside the software after this final report is produced.

Each state has been known to release its own NAPLAN state averages based on different statistical modeling.  As NAPLAN is a national program administered by ACARA, we use their figures, not the state's figures. Secondly, ACARA treats outlier data in a more statistically correct manner—a procedure which has national agreement and "smooths" the effect of having just a few too many or just a few too few students below national minimum standard.